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Effect of Blade Inclining Angle on Internal Characteristic of Hydraulic Retarder Hui XIAO 1,a , Yaxu CHU 2,b 1,2Automotive and Architectural Engineering College of Beihua University,Jilin 132013,China a983136165@qq.com bcyx-1964@sina.com Keywords: Hydrodynamic retarder; Vane degree; Turbulent flow; Numerical simulation Abstract: Based on CFD software platform the numerical simulation of internal characteristic of hydraulic retarder was performed by moving mesh method with the RNG turbulence model and the SIMPLEC algorithm simultaneously, the internal characteristics of velocity and pressure distribution were analyzed through the numerical simulation and post-processing.
Comparing the calculation braking torque with the simulation results.
The research in the paper uses CFD to figure out the influence of different inclining angles on the performance of hydraulic retarder, finally to select the best parameters.
CFD Numerical Simulation Calculating fluid dynamics, shortened as CFD, analyses some physical phenomenon like fluid flowing and heat conducting.
Commercial Vehicle, (2007) (1);99 [2] Liu Zenggang, Zhang Bingrong and Li Mo, Discussion on the Development and Regulations of Automobile Retarder[J].Urban Vehicle,(2006) (2): 51-53 [3] Huang Jungang, Li Changyou and Tong Jun, Analysis of Key Factors Influencing on the Braking Torque of Hydraulic Retarder[J].Machine Tool & Hydraulics, (2010), 38(15): 77—80 [4] Wang Feng, Yan Qingdong and Ma Yue, Prediction and Analysis on the Performance of Hydraulic Retarder based on CFD Technology[J].Journal of System Simulation, (2007),19(6): 1390—1392 [5] He Ren, Yan Jun and Lu Ming, Three-Dimensional Numerical Simulation and Performance Prediction of Hydraulic Retarder[J].Chinese Journal of Automotive Engineering, (2009), 31(3): 250—252, 266 [6] Li Xuesong, Research on the Parameter Optimization Method of Automotive Hydraulic Retarder Based on Unsteady Flow Field Analysis[D].Changchun, Jilin University, (2010) [7] Yan Jun and He Ren, analysis on the performance of Hydraulic Retarder with Different

Guangzhou, 510700 aljou@scut.edu.cn, bnanhuowu@gmail.com, cdeyu@scut.edu.cn Keywords: Ducted Propeller, CFD, Hydrodynamic Performance Abstract.
In recent years, compared with experiment research, numerical simulation has advantages of low-cost and short-cycle, and can obtain complete data and simulate the measurement of various data in practical operation process.
CFD is widely used in the numerical simulation of flow field.
Because of its adaptability and accuracy [1], CFD gradually becomes an important tool in hydrodynamic research and its application fields have gradually expanded.
In the CFD simulation of ducted propeller hydrodynamic calculation, in order to simulate the different non-uniform wake fields, the inlet is defined by UDF, and the averaged inlet velocity is 3.5m/s. 3.

In this paper, based on fluid dynamics software CFD and criteria Reynolds k-ε turbulence model, wind field of the village flat roof with parapet is studied using the numerical simulation technology.
CFD turbulence models currently include Spalart-Allmaras model, k-ε model, k-ω model, the Reynolds stress model (RSM), large eddy simulation model (LES), etc, of which the standard k-ε model is proposed by the Launder and Spalding.
Therefore, a numerical simulation is conducted on the wind field of a flat roof with parapet using CFD software fluent 6.3, in which criteria Reynolds k-ε turbulence model is selected, and the wind pressure data in different wind angles is processed and analyzed.
Numerical Simulation Standard k-ε model.
Near-field pollutant dispersion in the built environment by CFD and wind tunnel simulations[J].

., Hanulova č. 9, 841 01 Bratislava, Slovakia adagmara.cehelova@stuba.sk, bjanak@simulaciebudov.sk, cboris.bielek@stuba.sk Keywords: wind, buildings aerodynamic, airflow, Venturi effect, CFD simulation Abstract.
CFD simulations are today the preferred method of estimating of expected wind effects on pedestrians and buildings.
Study was conducted by CFD simulation with software OpenFOAM.
The simulation was settings based on previous studies from Richard and Hoxey (1993) and Blocken, Carmeliet and Stathopoulos (2007) that have dealt at issues of CFD modeling atmospheric boundary layer [2], [3], [6] .
CFD simulation of the atmospheric boundary layer: wall function problems.

This research used CFD software to analyze the heat transfer from microprocessor in mini wind tunnel.
The model used in this simulation consists of a wind tunnel contain a motherboard and four microprocessor.
The side view of the simulation setup for electronic packaging is shown in Figure 1.
The two types of thermal interface material were used in this simulation setup (NCT & Gad Pad 2500).
Fig. 1: Simulation Setup for thermal interface material (side view) Table 1: Dimension of Components Used in Simulation.

CFD Simulation of Flow in Random Packing Columns with Seawater Desulfurization GAO mei-shan1,a, WANG shi-he1,b, WANG xiao-ming2, Guo ming-chun3,c 1College of civil engineering, Southeast University, Nanjing, China 2State Power Environmental Protection Research Institute, Nanjing, China 3Shanghai Huolin Engineering Plastics Co., Ltd., Shanghai, China asandy_gms@163.com, bwshhj@seu.edu.cn, cgmcjz1120@sina.com Keywords: seawater desulfurization; packing columns; CFD simulation; Abstract.
Based on the volume average method, gas-liquid two-phase flow CFD model is established to describe the random packing column in seawater desulfurization.
With CFD as a tool, the test can be carried out under variable parameters and conditions at lower cost and less time and the distribution of fluid flow can be obtained more intuitive and more detailed than with experiment, therefore, the impacts of flow distribution on heat and mass transfer can be learned further more by study on the simulation of flow in packed column of seawater desulfurization and the variable parameters and conditions testes can be carried out at a lower cost so as to provide a guide for engineering design.
Mathematical model Simulation of random packing column gas-liquid two-phase flow, generally regarded the movement of gas that is the piston flow.
On the one hand, the impact of this simplified simulation on the velocity is very small, on the other hand, calculation can be simplified so as to make calculation stable and converge.

ananodogy@yahoo.com.tw blinsiraya@yahoo.com.tw cta.yang168@msa.hinet.net Keywords: Stratified air conditioning design, Assembly hall, CFD Abstract.This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between “all-zone air conditioning design” and “stratified air conditioning design”.
The study uses CFD simulation software to compare the indoor environment quality of the stratified air conditioning design with the all-zone air conditioning design.
Fig. 1 All-zone air conditioning design Fig. 2 Stratified air conditioning design (Blue arrows mean air outlets, red arrows mean return vents) Methodology 1) Study methods and tools Computational fluid dynamics (CFD) has been widely regarded as a useful tool in the building environment in recent years, so this study also uses CFD software to simulate the indoor air environment.
The all-zone air conditioning design The stratified air conditioning design Section A (21.0℃) (20.1℃) Section B (22.2℃) (20.5℃) Section C (23.5℃) (21.8℃) Fig. 5 Temperature graphs of three sections (The values are average temperature of seating and stage areas) Conclusion In this study, the three conclusions are as follows: 1) The simulation of the all-zone air conditioning design clearly shows that most cold air is wasted in the top space of the assembly hall.
However, as the distance between air outlets and people in the assembly hall is closer, the location of air outlets and return vents must be carefully designed to avoid excessive or inadequate airflow. 3) The results of CFD simulation comparison of the all-zone air conditioning design with the stratified air conditioning design under the same airflow volume reveal that stratified design is better in the wind velocity and temperature fields, it can increase 0.02~0.09m/s of the wind velocity and decrease about 2℃ temperature than the all-zone air conditioning design, They prove that the use of stratified air conditioning design in assembly halls is feasible and useful.

In this study, numerical simulation by using computational fluid dynamics (CFD) codes were conducted to investigate the influence of alternative layouts for air distribution in a full scale newly constructed data center.
Numerical study through CFD simulation can not only identify the best practice for airflow distribution, but also provide the energy-efficient and cost-effective HVAC system specific for data center facility.
By using CFD modeling, the rack intake temperature can be determined.
Herrlin [5] also developed the method for optimizing equipment cooling effectiveness using RCI through CFD simulation.
In this study, numerical simulation of the data center in our university was conducted.

However, CFD simulation ,as an inseparable part of engine design, has helped researchers and engineers to overcome these problems.
Engine designers take advantage of CFD simulations to develop better understanding of different stages of engine cycle to be able to make engines satisfy stringent emission and fuel consumption standards[8].The KIVA-3V code is one the effective CFD tools that has been developed in Los Alamos laboratory to help studying the whole engine process through three dimensional modeling..
The mesh that is used in the CFD simulation is shown in Fig.2 The mesh is generated by ICEM-CFD.
Mesh generated in ICEM-CFD KIVA-3V is a CFD code that solves the Navier-Stocks equation for three dimensional, unsteady, compressible, turbulent and reacting flow.
"In-cylinder airflow of automotive engine by quasi-direct numerical simulation."

Furthermore, some suggestions are put forward through these simulation results.
In order to obtain the boundary conditions of CFD analysis, 1-D engine cycle simulation model at the rated speed of 6000rpm is built to calculate the crank angle-varying mass flow rate and gas temperature at inlet and outlet of exhaust manifold.
Fig. 1 shows a finite volume mesh model for CFD analysis.
The CFD analysis of external flow field is calculated by the simulation of bench test of steady flow field.
The simulation focuses on surfaces in contact with the outer surfaces of exhaust manifold, where we refine during the meshing process.